Beneficial effects of statins on outcomes in pneumonia: a systematic review and meta-analysis

OBJECTIVES

There exist reports that statin treatment has beneficial effects for patients with pneumonia. The objective of this study was to evaluate whether the available published data support that statins as adjunctive therapy could reduce mortality associated with pneumonia and, thus, help to assess whether a randomized controlled study is warranted.

MATERIALS AND METHODS

A meta-analysis of observational studies such as cohort studies and case-control studies identified in Pubmed, Scopus, EMBASE, the Cochrane Central Register of Controlled Trials and Clinicaltrials.gov. Eligible patients were adults with pneumonia. Studies that reported mortality of pneumonia grouped by statins usage were included. Data was analyzed and pooled using Revman 5.1.

RESULTS

Fourteen studies with 269,739 participants were included in this study. Pooled analysis showed that statin treatment was associated with lower 30-day mortality, with an OR of 0.44 (95% CI, 0.29-0.67), and an adjusted OR of 0.59 (95% CI 0.48-0.73, NNT30d = 19). Statin therapy was also associated with lower long-term (> 30 days) mortality, with an OR of 0.49 (95% CI, 0.29-0.84) and an adjusted OR of 0.65 (95% CI, 0.51-0.82, NNTlong-term = 15). For pneumonia inpatients, the raw data demonstrated no significant benefit from statin therapy (OR = 0.86, 95% CI, 0.56-1.34). Adjusted data showed a marginal benefit (adjusted OR = 0.89, 95% CI, 0.81-0.97, NNTinpatient = 230). Subgroup analysis revealed that current statin users might have better outcomes than recent or past statins users.

CONCLUSIONS

This meta-analysis supports that patients who happen to be receiving statin therapy have less mortality from pneumonia. However, it remains unclear whether initiation of statins at time of diagnosis is beneficial. There is only modest evidence to support the value of a well-designed randomized controlled clinical trial.

Liver kinase B1 regulates the centrosome via PLK1

Liver kinase B1 (LKB1) is a tumor suppressor mutationally inactivated in Peutz-Jeghers syndrome (PJS) and various sporadic cancers. Although LKB1 encodes a kinase that possesses multiple functions, no individual hypothesis posed to date has convincingly explained how loss of LKB1 contributes to carcinogenesis. In this report we demonstrated that LKB1 maintains genomic stability through the regulation of centrosome duplication. We found that LKB1 colocalized with centrosomal proteins and was situated in the mitotic spindle pole. LKB1 deficiency-induced centrosome amplification was independent of AMP-activated protein kinase (AMPK), a well-defined substrate of LKB1. Cells lacking LKB1 exhibited an increase in phosphorylated and total Polo-like kinase 1 (PLK-1), NIMA-related kinase 2 (NEK2), and ninein-like protein (NLP). Overexpression of active PLK1 (T210D) reversed the inhibition of LKB1 on centrosome amplification. In contrast, depletion of PLK1 with siRNA or suppression of PLK1 kinase activity with BTO-1 (5-Cyano-7-nitro-2-benzothiazolecarboxamide-3-oxide) abrogated LKB1 deficiency-induced centrosome amplification. We further characterized that LKB1 phosphorylated and activated AMPK-related kinase 5 (NUAK1 or ARK5) that in turn increased the phosphorylation of MYPT1, enhanced the binding between MYPT1-PP1 and PLK1, and conferred an effective dephosphorylation of PLK1. More importantly, we noted that LKB1-deficient cells exhibited multiple nuclear abnormalities, such as mitotic delay, binuclear, polylobed, grape, large, and micronuclear. Immediate depletion of LKB1 resulted in the accumulation of multiploidy cells. Expression of LKB1 is reversely correlated with the levels of PLK1 in human cancer tissues. Thus, we have uncovered a novel function of LKB1 in the maintenance of genomic stability through the regulation of centrosome mediated by PLK1.

Room-temperature antiferromagnetic memory resistor

The bistability of ordered spin states in ferromagnets provides the basis for magnetic memory functionality. The latest generation of magnetic random access memories rely on an efficient approach in which magnetic fields are replaced by electrical means for writing and reading the information in ferromagnets. This concept may eventually reduce the sensitivity of ferromagnets to magnetic field perturbations to being a weakness for data retention and the ferromagnetic stray fields to an obstacle for high-density memory integration. Here we report a room-temperature bistable antiferromagnetic (AFM) memory that produces negligible stray fields and is insensitive to strong magnetic fields. We use a resistor made of a FeRh AFM, which orders ferromagnetically roughly 100 K above room temperature, and therefore allows us to set different collective directions for the Fe moments by applied magnetic field. On cooling to room temperature, AFM order sets in with the direction of the AFM moments predetermined by the field and moment direction in the high-temperature ferromagnetic state. For electrical reading, we use an AFM analogue of the anisotropic magnetoresistance. Our microscopic theory modelling confirms that this archetypical spintronic effect, discovered more than 150 years ago in ferromagnets, is also present in AFMs. Our work demonstrates the feasibility of fabricating room-temperature spintronic memories with AFMs, which in turn expands the base of available magnetic materials for devices with properties that cannot be achieved with ferromagnets.

Development of Methanoculleus-specific real-time quantitative PCR assay for assessing methanogen communities in anaerobic digestion

AIM

To develop a Methanoculleus-specific real-time quantitative PCR (RT-qPCR) assay with high coverage and specificity for the analysis of methanogenic populations in anaerobic digestion.

METHODS AND RESULTS

A Methanoculleus-specific primer/probe set for RT-qPCR was designed in this study based on all Methanoculleus 16S rRNA gene sequences in Ribosomal Database Project (RDP) according to TaqMan chemistry. The newly designed primer/probe set was shown to have high coverage and specificity by both in silico and experimental analyses. Amplification efficiency of the Methanoculleus-specific primer/probe set was determined to be ideal for RT-qPCR applications. Subsequent field testing on anaerobic digesters showed that results from RT-qPCR were consistent with those from clone library analysis, validating the accuracy of the RT-qPCR assay.

CONCLUSIONS

The Methanoculleus-specific RT-qPCR assay designed in this study can serve as a rapid and effective tool for the quantification of Methanoculleus populations in anaerobic digestion.

SIGNIFICANCE AND IMPACT OF THE STUDY

Methanoculleus populations represent important members of archaeal communities in methanogenic processes, necessitating the need to develop effective tools to monitor Methanoculleus population abundance. The RT-qPCR developed in this study provides an essential tool for the quantification of Methanoculleus populations in anaerobic digestion and for the understanding of the functions of these methanogens in anaerobic biotransformation.

Atomic force microscopic investigation of respiratory syncytial virus infection in HEp-2 cells

Respiratory syncytial virus (RSV) primarily causes bronchiolitis and pneumonia in infants. In spite of intense research, no safe and effective vaccine has been developed yet. For understanding its pathogenesis and development of anti-RSV drugs/therapeutics, it is indispensable to study the RSV-host interaction. Although, there are limited studies using electron microscopy to elucidate the infection process of RSV, to our knowledge, no study has reported the morphological impact of RSV infection using atomic force microscopy. We report the cytoplasmic and nuclear changes in human epidermoid cell line type 2 using atomic force microscopy. Human epidermoid cell line type 2 cells, grown on cover slips, were infected with RSV and fixed after various time periods, processed and observed for morphological changes using atomic force microscopy. RSV infected cells showed loss of membrane integrity, with degeneration in the cellular content and cytoskeleton. Nuclear membrane was disintegrated and nuclear volume was decreased. The chromatin of the RSV infected cells was condensed, progressing towards degeneration via pyknosis and apoptosis. Membrane protrusions of ~150-200 nm diameter were observed on RSV infected cells after 6 h, suggestive of prospective RSV budding sites. To our knowledge, this is the first study of RSV infection process using atomic force microscopy. Such morphological studies could help explore viral infection process aiding the development of anti-RSV therapies.

The anti-tumoral efficacy of a docetaxel-loaded liposomal drug delivery system modified with transferrin for ovarian cancer

To reduce the toxic effect on normal cells and improve the treatment effects of docetaxel, a novel transferrin modified docetaxel-loaded long circulating liposome for ovarian tumor was established for the first time. The transferrin-modified long-circulating liposomes loaded with docetaxel (TF-LP-DOC) were prepared by the post-insertion method and exhibited excellent characteristics in terms of particle size, encapsulation efficiency and stability. We investigated the targeting efficiencies of liposomes by the cellular uptake in vitro and biodistribution in vivo, and identified the therapeutic effects using cytotoxicity experiment (in vitro)and tumor growth inhibition (in vivo) on ovarian cancer. The in vitro and in vivo results showed that TF-LP-DOC were successfully established and presented an enhanced targeting ability. With decreased side effect and improved anti-tumor efficacy of chemotherapeutic drugs, TF-LP-DOC proved itself to be a very promising tumor targeted drug delivery system.

Piperlongumine induces autophagy by targeting p38 signaling

Piperlongumine (PL), a natural product isolated from the plant species Piper longum L., can selectively induce apoptotic cell death in cancer cells by targeting the stress response to reactive oxygen species (ROS). Here we show that PL induces cell death in the presence of benzyloxycarbonylvalyl-alanyl-aspartic acid (O-methyl)-fluoro-methylketone (zVAD-fmk), a pan-apoptotic inhibitor, and in the presence of necrostatin-1, a necrotic inhibitor. Instead PL-induced cell death can be suppressed by 3-methyladenine, an autophagy inhibitor, and substantially attenuated in cells lacking the autophagy-related 5 (Atg5) gene. We further show that PL enhances autophagy activity without blocking autophagy flux. Application of N-acetyl-cysteine, an antioxidant, markedly reduces PL-induced autophagy and cell death, suggesting an essential role for intracellular ROS in PL-induced autophagy. Furthermore, PL stimulates the activation of p38 protein kinase through ROS-induced stress response and p38 signaling is necessary for the action of PL as SB203580, a p38 inhibitor, or dominant-negative p38 can effectively reduce PL-mediated autophagy. Thus, we have characterized a new mechanism for PL-induced cell death through the ROS-p38 pathway. Our findings support the therapeutic potential of PL by triggering autophagic cell death.

Enhanced tumor accumulation and cellular uptake of liposomes modified with ether-bond linked cholesterol derivatives

Novel liposomal formulations based on cholesterol modification had been designed previously by our lab, but we found them with a poor stability and short half-life, especially in blood circulation. The results might be attributed to the hydrolysis of ester linked cholesterol derivatives by esterase in plasma. Thus, in this study, we newly synthesized ether-linked cholesterol derivatives and compared them to other preparations. A comparison with the substrate cholesterol-PEG2000-maleimide showed that ether-linked cholesterol-PEG2000-maleimide could relatively maintain integrity in serum, with only a small mottle emerging on TLC (thin-layer chromatography) plates through the experiment. Then a cell-penetrating peptide TAT was attached to the distal end of CHO-PEG2000 to prepare liposomes and to further evaluate the two cholesterol derivatives. Optimized liposomes (65:35, lipid/cholesterol, molar ratio) composed of 3% CHO-PEG2000 and 3% CHO-PEG2000-TAT showed good stability in 50%FBS (fetal bovine serum). In vitro experiments showed that as incubation time prolonged, ether-linked-TAT LIP showed a 3.67-fold higher uptake amount than ester-linked-TAT LIP. In vivo, ether-linked-TAT LIP accumulated better in tumors and had a 40% higher cellular uptake amount. Altogether, we could conclude that our newly ether-linked cholesterol derivatives possessed better stability especially in blood circulation which led to increased tumor cellular uptake in vitro and in vivo. Our study may offer a better way in cholesterol modification to prepare functionalized liposomes.

Reciprocal interaction between intestinal microbiota and mucosal lymphocyte in cynomolgus monkeys after alemtuzumab treatment

It has been known that the gut microbiota plays a central role in shaping normal mucosal immunity, however, little information is available whether the variability of mucosal lymphocytes impacts the commensal flora. Here, we applied a cynomolgus monkey model to characterize the structure and composition of the gut microbiota in response to lymphocyte depletion and to determine their potential association. Molecular profiling of 16S rDNA showed that the intestinal microbiota composition was perturbed after the depletion of mucosal lymphocytes and were recovered following the repopulation. Some specific bacteria from the orders Lactobacillales, Enterobacteriales and Clostridiales, and the genus Prevotella and Faecalibacterium, were primarily responsible for the variations of the gut microbiota after lymphocyte depletion. Interestingly, the species richness of the ileal mucosal microbiota was associated the proportions of TCRαβ+ or TCRγδ+ T cells (p<0.01). We demonstrate for the first time the feature of intestinal microbiota composition after lymphocyte depletion and provide novel evidence that the perturbation of gut microbiota is associated with lymphocyte depletion. It may contribute to understand the relationship between gut commensal microbiota and mucosal immune system. Study results provide insight into biological activity of alemtuzumab in intestinal barrier in organ transplantation.

Chemokines fluctuate in the progression of primary breast cancer

BACKGROUND

Many studies have demonstrated that chemokines and their receptors play important roles in breast cancer. However, few of them focus on the concentration change of chemokines along breast cancer evolvement, especially for primary breast cancer.

PURPOSE OF THE STUDY

To investigate the effects of chemokines and their receptors on different stage of primary breast cancer, and to find correlationships between chemokines, between different clinico-pathological characters of patients or between chemokines and different clinico-pathological characters of patients.

PATIENTS AND METHODS

We evaluated and compared the concentration of 10 chemokines and receptors in serum of patients diagnosed as breast benign change, epithelial proliferation (present only or with atypia), in situ carcinoma and invasive carcinoma.

RESULTS

Our oneway ANOVA analysis results showed that in all cases from benign diseases to invasive carcinoma, the concentration of CXCL8, CXCR4 and CXCL12 was significantly different; in benign subgroups (benign change, benign change with proliferation, atypia), the concentration of CCL2 and CCR5 was significantly different; in invasive carcinoma cases, DARC concentration was significantly correlated with the relapse risk of patients.

CONCLUSIONS

The correlation analysis indicated the great crosstalk between chemokines and receptors in the course of primary breast cancer; Ki67 expression was associated with CXCL5 and CXCL7 concentration; tumor size was associated with CXCL8 concentration; and the correlation analysis between clinico-pathological characters of patients showed that pathological diagnosis was correlated with tumor size, relapse risk and Ki67 expression; nuclear grades was correlated with LN metastasis, ER status, PR status and the breast cancer genotype; LN metastasis was correlated with relapse risk. Our findings clearly indicated for the first time that the fluctuations of chemokines and receptors contributed to the evolving of primary breast cancer.

Peritubular capillaritis in early renal allograft dysfunction is an indicator of acute rejection

BACKGROUND

Kidneys showing acute rejection (AR) processes often are accompanied by various levels of peritubular capillaritis (Ptc), especially cases of acute humoral rejection (AHR). However, it is not known whether the presence of Ptc alone is sufficient evidence of allograft rejection. This study was performed to determine the diagnostic value of Ptc as a marker for AR among cases of early renal allograft dysfunction.

METHODS

Fifty-three AR showed C4d deposition in the peritubular capillaries (PTCs; C4d+AR group), 50 AR were without C4d deposition (C4d-AR group), 30 had Ptc alone (Ptc group), 28 had acute tubular necrosis (ATN group), and 78 were surveillance biopsies (control group).

RESULTS

Analyzing the immunophenotype of infiltrating T lymphocytes and serum antibodies, discovered that 85.9% of control biopsies presented with a regulatory phenotype. Among the Ptc cohort, 93.3% of biopsies showed the cytotoxic phenotype with no significant different between C4d+AR and C4d-AR (96.2% vs 92.0%). We also observed the prevalence of panel-reactive antibody (PRA) and major-histocompatibility-complex class I chain-related gene A (MICA) antibodies to be increased among Ptc (30.0% and 43.3%, respectively), albeit not significantly different from C4d+AR (49.1% and 39.6%, respectively). The prevalences were low in other groups.

CONCLUSIONS

These results implied that Ptc in biopsy specimens from patients with early renal allograft dysfunction was an indicator of AR, especially AHR.

Modulating vascular intimal hyperplasia using HSV-1 mutant requires activated MEK

Outcomes of cardiovascular procedures, such as angioplasty and stent or bypass grafting are limited by failure, predominantly caused by pathological smooth muscle cell (SMC) proliferation, known as intimal hyperplasia. Local delivery of a genetically engineered herpes simplex virus (HSV) is known to block vascular SMC proliferation while allowing for re-endothelialization. However, the mechanism this mutant virus uses to prevent SMC hyperplasia is unknown. The Ras signaling cascade is activated in SMCs undergoing hyperplasia leading to phosphorylation of the mitogen-activated protein kinase (MAPK). In this study we tested the hypothesis that MAPK kinase (MEK) activity is the molecular basis by which SMCs are susceptible to mutant HSV. We show that genetically engineered herpes simplex-1 viruses (HSV-1) can target proliferating SMCs. We demonstrate that the molecular basis of this HSV-1 anti-proliferative effect is MEK activation in SMCs. We demonstrate efficacy and practicality of the MEK-dependent HSV-1 for the treatment of intimal hyperplasia in a clinically relevant in vivo model. Important to this strategy is the ability to modulate the effects by controlling viral dose. These results propel genetically engineered HSV-1 therapy towards clinical evaluation in treatment of intimal hyperplasia.

Investigation of Wide Bandgap Semiconductors for Thermoelectric Applications

Thermoelectric materials with stable mechanical and chemical properties at high temperature are required for power generation applications. For example, gas temperatures up to 1000°C are normally present in the waste stream of industrial processes and this can be used for electricity generation. There are few semiconductor materials that can operate effectively at these high temperatures. One solution may be the use of wide bandgap materials, and in particular GaN-based materials, which may offer a traditional semiconductor solution for high temperatures thermoelectric power generation. In particular, the ability to both grow GaN-based materials and fabricate them into devices is well understood if their thermoelectric properties are favorable. To investigate the possibility of using III-Nitride and its alloys for thermoelectric applications, we synthesized and characterized room temperature thermoelectric properties of metal organic chemical vapor deposition grown GaN and InGaN with different carrier concentrations and indium compositions. The promising value of Seebeck coefficients and power factors of Si-doped GaN and InGaN indicated that these materials are suitable for thermoelectric applications.

Preservation of immunorecognition by transferring cells from 10% neutral buffered formalin to 70% ethanol

Prolonged fixation of cells and tissues in 10% neutral buffered formalin (NBF) may decrease immunorecognition in some antigen-antibody pairs. Short fixation in 10% NBF followed by transfer to 70% ethanol has been used to overcome these effects, but the effects of this transfer on immunorecognition have not been explored adequately. We used two cell lines, DU145 (prostate cancer) and SKOV3 (ovarian cancer), grew them on coverslips and fixed them with 10% NBF at room temperature for 5 min and 12, 15, 18, 36, 108 and 180 h. Aliquots of the same cells were fixed in 10% NBF for 12 h, then transferred to 70% ethanol for 3, 6, 24, 96 and 168 h. Immunostaining with PCNA, Ki67-MIB-1, cytokeratins AE1/AE3 and EGFr was done concomitantly. In both cell lines, immunorecognition decreased between 18 and 36 h of fixation in 10% NBF for PCNA, Ki67-MIB-1 and cytokeratins AE1/AE3. By 108 to 180 h of 10% NBF exposure, there was complete loss of immunorecognition of PCNA and extensive loss of Ki67-MIB-1 and cytokeratins AE1/AE3. The effects on EGFr immunorecognition were less. Transfer to 70% ethanol after fixation for 12 h in 10% NBF preserved immunorecognition of the antibodies.

Orthorhombic BiFeO3

A new orthorhombic phase of the multiferroic BiFeO3 has been created via strain engineering by growing it on a NdScO(3)(110)(o) substrate. The tensile-strained orthorhombic BiFeO3 phase is ferroelectric and antiferromagnetic at room temperature. A combination of nonlinear optical second harmonic generation and piezoresponse force microscopy revealed that the ferroelectric polarization in the orthorhombic phase is along the in-plane {110}(pc) directions. In addition, the corresponding rotation of the antiferromagnetic axis in this new phase was observed using x-ray linear dichroism.

Nanoscale phase boundaries: a new twist to novel functionalities

In functional materials, nanoscale phase boundaries exhibit exotic phenomena that are notably absent in their parent phases. Over the past two decades, much of the research into complex oxides (such as cuprate superconductors, CMR manganites and relaxor ferroelectrics) has demonstrated the key role that nanoscale inhomogeneities play in controlling the electronic and/or ionic structure of these materials. One of the key characteristics in such systems is the strong susceptibility to external perturbations, such as magnetic, electric and mechanical fields. A direct consequence of the accommodation of a large number of cationic substitutions in complex oxides is the emergence of a number of physical phenomena from essentially the same crystal framework. Recently, multiferroic behavior, which is characterized by the co-existence and potential coupling of multiple ferroic order parameters, has captured considerable worldwide research interest. The perovskite, BiFeO(3), exhibits robust ferroelectricity coupled with antiferromagnetism at room temperature. A rather unique feature of this material system is its ability to "morph" its ground state when an external mechanical constraint is imposed on it. A particularly striking example is observed when a large (~4 to 5%) compressive strain is imposed on a thin film through the epitaxial constraint from the underlying substrate. Under these conditions, the ground state rhombohedral phase transforms into a tetragonal-like (or a derivative thereof) phase with a rather large unit cell (c/a ratio of ~1.26). When the epitaxial constraint is partially relaxed by increasing the film thickness, this tetragonal-like phase evolves into a "mixed-phase" state, consisting of a nanoscale admixture of the rhombohedral-like phase embedded in the tetragonal-like phase. Such a system gives us a new pathway to explore a variety of mechanical, magnetic and transport phenomena in constrained dimensions. This article reviews our progress to date in this direction and also captures some possible areas of future research. We use the electromechanical response and the magnetic properties as examples to illustrate that its novel functionalities are intrinsically due to the phase boundaries and not the constituent phases. The possible origin of the giant piezoelectric response and enhanced magnetic moment across the boundaries is proposed based on the flexoelectric and flexomagnetic effects.

Human osteosarcoma CD49f(-)CD133(+) cells: impaired in osteogenic fate while gain of tumorigenicity

The biological relationships among self-renewal, tumorigenicity, and lineage differentiation of human osteosarcoma-initiating cells (OSIC) remain elusive, making it difficult to identify and distinguish OSIC from osteosarcoma-forming cells (OSFC) for developing OSIC-targeted therapies. Using a new inverse lineage tracking strategy coupled with serial human-to-mouse xenotransplantation, we identified a subpopulation of osteosarcoma cells with OSIC-like properties and sought to distinguish them from their progeny, OSFC. We found that serial transplantation of cells from different osteosarcoma cell lines and primary osteosarcoma tissues progressively increased the CD49f⁺ subpopulation composing the bulk of the osteosarcoma mass. These CD49f⁺ cells displayed characteristics of OSFC: limited in vivo tumorigenicity, weak lineage differentiation, more differentiated osteogenic feature, and greater chemo-sensitivity. By contrast, their parental CD49f⁻CD133⁺ cells had an inhibited osteogenic fate, together with OSIC-like properties of self-renewal, strong tumorigenicity, and differentiation to CD49f⁺ progeny. Hence, the CD49f⁻CD133⁺ phenotype appears to identify OSIC-like cells that possess strong tumorigenicity correlated with an impaired osteogenic fate and the ability to initiate tumor growth through generation of CD49f⁺ progeny. These findings advance our understanding of OSIC-like properties and, for the first time, provide a much-needed distinction between OSIC and OSFC in this cancer.

Flow injection spectrofluorimetric determination of reserpine in tablets by on-line acetone sensitized photochemical reaction

On-line photochemical reaction of reserpine in the presence of acetone was investigated. Acetone was found to speed up the on-line photochemical conversion of reserpine into an intensively fluorescent compound. Not only reaction acidity but also the acetate buffer concentration affected the on-line photochemical induced fluorescence signal. Based on the observation an automated flow injection photochemical fluorimetric approach was developed. An injected sample zone was carried by a water stream to be merged with a acetate buffer (pH 3.4) solution containing 0.02% acetone in a knotted PTFE reactor (KR), which was freely coiled around a 6-W low pressure mercury lamp. While passing the KR, reserpine was transformed into an intensively fluorescent compound. It was on-line detected in a flow-through cell at the emission wavelength of 490 nm and excitation wavelength of 386 nm. At optimized conditions, a detection limit 0.45 mug l(-1) was achieved at a sampling rate of 90 h(-1). Eleven determinations of a 0.5 mg l(-1) reserpine standard solution gave a R.S.D. of 0.3%. The linear dynamic range of reserpine calibration curve was 0.01-0.75 mg l(-1). The proposed method was applied to assay the reserpine content in tablets and to monitor the dissolution profile of reserpine tablets. Satisfactory results were obtained for both the assays and dissolution studies.

Evidence of sharp and diffuse domain walls in BiFeO3 by means of unit-cell-wise strain and polarization maps obtained with high resolution scanning transmission electron microscopy

Domain walls (DWs) substantially influence a large number of applications involving ferroelectric materials due to their limited mobility when shifted during polarization switching. The discovery of greatly enhanced conduction at BiFeO(3) DWs has highlighted yet another role of DWs as a local material state with unique properties. However, the lack of precise information on the local atomic structure is still hampering microscopical understanding of DW properties. Here, we examine the atomic structure of BiFeO(3) 109° DWs with pm precision by a combination of high-angle annular dark-field scanning transmission electron microscopy and a dedicated structural analysis. By measuring simultaneously local polarization and strain, we provide direct experimental proof for the straight DW structure predicted by ab initio calculations as well as the recently proposed theory of diffuse DWs, thus resolving a long-standing discrepancy between experimentally measured and theoretically predicted DW mobilities.

Interface control of bulk ferroelectric polarization

The control of material interfaces at the atomic level has led to novel interfacial properties and functionalities. In particular, the study of polar discontinuities at interfaces between complex oxides lies at the frontier of modern condensed matter research. Here we employ a combination of experimental measurements and theoretical calculations to demonstrate the control of a bulk property, namely ferroelectric polarization, of a heteroepitaxial bilayer by precise atomic-scale interface engineering. More specifically, the control is achieved by exploiting the interfacial valence mismatch to influence the electrostatic potential step across the interface, which manifests itself as the biased-voltage in ferroelectric hysteresis loops and determines the ferroelectric state. A broad study of diverse systems comprising different ferroelectrics and conducting perovskite underlayers extends the generality of this phenomenon.

Observation of electron-antineutrino disappearance at Daya Bay

The Daya Bay Reactor Neutrino Experiment has measured a nonzero value for the neutrino mixing angle θ(13) with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GWth reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a 43,000 ton-GWth-day live-time exposure in 55 days, 10,416 (80,376) electron-antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is R=0.940±0.011(stat.)±0.004(syst.). A rate-only analysis finds sin(2)2θ(13)=0.092±0.016(stat.)±0.005(syst.) in a three-neutrino framework.

Electric-field control of nonvolatile magnetization in Co40Fe40B20/Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O3 structure at room temperature

We report a large and nonvolatile bipolar-electric-field-controlled magnetization at room temperature in a Co(40)Fe(40)B(20)/Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O(3) structure, which exhibits an electric-field-controlled looplike magnetization. Investigations on the ferroelectric domains and crystal structures with in situ electric fields reveal that the effect is related to the combined action of 109° ferroelastic domain switching and the absence of magnetocrystalline anisotropy in Co(40)Fe(40)B(20). This work provides a route to realize large and nonvolatile magnetoelectric coupling at room temperature and is significant for applications.

Magnetotransport at domain walls in BiFeO3

Domain walls in multiferroics can exhibit intriguing behaviors that are significantly different from the bulk of the material. We investigate strong magnetoresistance in domain walls of the model multiferroic BiFeO3 by probing ordered arrays of 109° domain walls with temperature- and magnetic-field-dependent transport. We observe temperature-dependent variations in the transport mechanism and magnetoresistances as large as 60%. These results suggest that by locally breaking the symmetry of a material, such as at domain walls and structural interfaces, one can induce emergent behavior with properties that deviate significantly from the bulk.

P2-06-03: Differential Expression of Breast Cancer-Associated Genes between Stage- and Age-Matched Tumor Specimens from African- and Caucasian-American Women Diagnosed with Breast Cancer

Background: Recent studies suggest that the poorer outcome of breast cancer patients observed in African-American women (AAW) may, in part, result from underlying genetic factors. The purpose of this study was to investigate gene expression differences between Caucasian-American women (CAW) and AAW that may contribute to this poorer prognosis.

Methods: The expression of genes involved in breast carcinoma prognosis, response to therapy, estrogen signaling, and tumor aggressiveness was assessed in age- and stage-matched CAW and AAW paraffin-embedded breast cancer specimens. The Wilcoxon-Mann-Whitney Test was used to identify genes with a significant difference in expression between CAW and AAW. To determine if the differentially expressed genes could segregate between the CAW and AAW, we performed semi-supervised principle component analysis (SSPCA).

Results: Twenty genes were differentially expressed between AAW and CAW. SSPCA incorporating these 20 genes separated AAW and CAW into two distinct groups. AAW were significantly (p &lt; 0.05) more likely to display aberrations in G1/S cell-cycle regulatory genes, decreased expression of cell-adhesion genes, and low to no expression of ESR1, PGR, ERBB2 and estrogen pathway targets.

Conclusions: The gene expression differences identified between AAW and CAW may contribute to more aggressive disease, resistance to therapy, enhanced metastatic potential and poor clinical outcome. Impact: These findings support the hypothesis that breast cancer specimens collected from AAW display distinct genetic differences compared to similar tissues obtained from CAW. Additional population-based studies are necessary to determine if these genetic variations contribute to the highly aggressive and treatment-resistant breast cancer phenotype frequently observed in AAW.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-06-03.

Nocardia infection in kidney transplant recipients: case report and analysis of 66 published cases

Nocardiosis is a rare but life-threatening opportunistic infection, especially in immune compromised patients, including kidney transplant recipients. Primary pulmonary infection is the most common clinical pattern, and can easily result in disseminated Nocardia infection if treatment therapy is not adequate at the beginning. In this article, we report a new case of disseminated nocardiosis (lungs, skin, and pericardium) after renal allograft transplantation. We also review the English literature published from 1980 to 2010 and analyze the clinical characteristics of nocardiosis in kidney transplant recipients.

Analysis of clinical data of patients with different outcomes after short-time insemination

The study is to analyse the clinical data of the two groups of patients with different fertilisation outcomes after short-time insemination and probe into short-time insemination indications. A retrospective study including 558 cycles of short-time insemination in our centre during January 2009 to June 2010 which were divided into two groups by the method of fertilisation, 472 cycles by IVF and 86 cycles by Re-ICSI group according to fertilisation conditions to and compare the differences between the two groups in the indexes of average female age, average male age, duration of infertility, forward-moving sperm counts, abnormal sperm rate, proportion of primary infertility, etc. The differences between the two groups have statistical significance in duration of infertility, forward-moving sperm counts, abnormal sperm rate and proportion of primary infertility (5.02 ± 3.12 versus 5.86 ± 3.35; 83.06 ± 78.55 versus 54.02 ± 61.78; 83.56 ± 5.24% versus 86.31 ± 5.26%; 56.87% versus 74.42%; P < 0.05). The discrepancy between the two groups has no statistical significance in average female age and average male age (P > 0.05). Duration of infertility, forward-moving sperm counts, abnormal sperm rate and previous pregnancy history have great significance to predict fertilisation failure, so decisions should be made on the basis of the above indexes when evaluating whether a patient should conduct short-time insemination.

Electric-field-induced magnetization reversal in a ferromagnet-multiferroic heterostructure

A reversal of magnetization requiring only the application of an electric field can lead to low-power spintronic devices by eliminating conventional magnetic switching methods. Here we show a nonvolatile, room temperature magnetization reversal determined by an electric field in a ferromagnet-multiferroic system. The effect is reversible and mediated by an interfacial magnetic coupling dictated by the multiferroic. Such electric-field control of a magnetoelectric device demonstrates an avenue for next-generation, low-energy consumption spintronics.

Microscopic origin of the giant ferroelectric polarization in tetragonal-like BiFeO(3)

We report direct experimental evidence for a room-temperature, ∼130  μC/cm(2) ferroelectric polarization from the tetragonal-like BiFeO(3) phase. The physical origin of this remarkable enhancement of ferroelectric polarization has been investigated by a combination of x-ray absorption spectroscopy, scanning transmission electron microscopy, and first principles calculations. A large strain-induced Fe-ion displacement relative to the oxygen octahedra, combined with the contribution of Bi 6s lone pair electrons, is the mechanism driving the large ferroelectric polarization in this tetragonal-like phase.

Lack of Keratinocyte Growth Factor Retards Angiogenesis in Cutaneous Wounds

This study investigated the effects of keratinocyte growth factor (KGF) on wound healing. Full-thickness excisional dorsal wounds were created on KGF knockout mice (KGF KO, n = 12) and wild-type C57BL/6 mice (WT, n = 12), and wound closure rates were measured. Immunohistochemical staining was used to investigate cell proliferation and blood vessel density by assessing Ki67 and CD31 protein levels, respectively, and real-time reverse transcription—polymerase chain reaction was used to measure vascular endothelial growth factor (VEGF) mRNA levels. No differences in the rate of wound closure were found between KGF KO and WT mice, however the KGF KO mice showed decreased proliferation of keratinocytes, angiogenesis and VEGF mRNA levels in vivo. These results suggest that KGF may play an important role in the regulation of VEGF gene expression and angiogenesis during wound healing.

Evaluation of a broadly protective Chlamydia-cholera combination vaccine candidate

The need to simultaneously target infections with epidemiological overlap in the population with a single vaccine provides the basis for developing combination vaccines. Vibrio cholerae ghosts (rVCG) offer an attractive approach for developing vaccines against a number of human and animal pathogens. In this study, we constructed a multisubunit vaccine candidate co-expressing the serovar D-derived Porin B and polymorphic membrane protein-D proteins of Chlamydia trachomatis and evaluated its ability to simultaneously induce broad-based chlamydial immunity and elicit a vibriocidal antibody response to the Vibrio carrier envelope. Intramuscular (IM) immunization with the vaccine candidate elicited high levels of antigen-specific genital mucosal and systemic Th1 cell-mediated and humoral immune responses against heterologous serovars and strains, including serovars E-H and L. Also, in addition to the multisubunit vaccine, the single subunit constructs conferred significant cross protection against the heterologous mouse strain, Chlamydia muridarum. Furthermore, all mice immunized with rVCG vaccine constructs responded with a significant rise in vibriocidal antibody titer, the surrogate marker for protection in cholera. These findings demonstrate the ability of the multisubunit vaccine to induce cross protective chlamydial as well as vibriocidal immunity and establish the possibility of developing a broadly efficacious Chlamydia-cholera combination vaccine.